Optimization of cosmetic formulations development using Box-Behnken design with response surface methodology: physical, sensory and moisturizing properties

Considering the importance of an adequate composition of the formulation in the development of stable, safe and effective cosmetic products, experimental design techniques are tools that can optimize the formulation development process. The objective of this study was to develop topical formulations using the Box-Behnken design with response surface methodology and evaluate its physical, sensory and moisturizing properties. The experimental design used in the first step allowed to identify and to quantify the influence of raw materials, as well as the interaction between them. In the second step, the analysis identified the influence of soy lecithin, the phytantriol and capric acid triglyceride and caprylic on the consistency index, stickiness and greasiness and skin hydration. Cetearyl alcohol, dicetyl phosphate and cetyl phosphate 10EO and acrylates/C10-30 alkylacrylate crosspolymer showed effects in rheological parameters. The addition of soy lecithin had significant effects in terms of consistency index, stickiness, oiliness and immediate moisturizing effects. Phytantriol showed effects on increasing consistency index and oiliness sensation. Thus, the experimental design was shown to be an effective tool for research and development of cosmetics, since it allowed the assessment of the individual and interaction effects of raw materials in the responses: rheological parameters, sensory and clinical efficacy.

Idiosyncratic reaction after injection of polyacrylate - polyalcohol copolymer

ABSTRACT Context: Polyacrylate-polyalcohol copolymer is a synthetic product, non-biodegradable, with low rate of therapeutic failure and lower incidence of reactions at the site of injection, when compared to biodegradable agents. We report an unprecedent, exuberant and persistent inflammatory reaction following injection of that substance. Patient: a 17 years-old patient with vesico-ureteral reflux and complete pyelocaliceal right duplication was submitted to treatment with polyacrylate-polyalcohol copolymer (STING technique). In the seventh day of post-operatory, she presented intense dysuria and hypogastric pain, without laboratory exams alterations; a symptomatic treatment was started. After two months, the symptoms persisted and an ultrasound detected thickening of bladder wall close to the uretero-vesical junction. After that exam, a cystostopic biopsy showed epithelial hyperplasia with increased edema of lamina propria, suggesting an adverse reaction to the polymer. After four months, there was complete remission, but the reflux persisted with the same grade. Hypothesis: This is an unprecedent reaction following injection of this copolymer. The presence of characteristics such as absence of infection, temporal relation between treatment and beginning of symptoms, and detection of epithelial hyperplasia at the local of injection reinforce the hypothesis of association of the substance and adverse reaction. In that patient, important complains motivated early investigation of urinary tract, that confirmed those aspects. Maybe if that reaction had occurred in patients with lower capacity of expression (such as in infants) it would be unnoticed.